// In file F:\matlab\ClassLoad.java

// Copyright 2004 Paul Milenkovic, 118 Shiloh Dr., Madison, WI 53705 U.S.A.
// Free software: Permission granted to use, copy, excerpt or share this
// source code and derived executables provided that this notice is maintained.

// ClassLoad: load/reload class loader for the Matlab environment.
// Example --
//     F:\matlab working directory, contains a public interface (not reloadable)
//     F:\matlab\myjava is subdirectory for reloadable Java class implementing
//         that interface (required).
//
// From Matlab command line
//     >>cl = ClassLoad('F:\\matlab\\myjava/')
// designates a directory F:\matlab\myjava to contain your reloadable class or 
// classes (must be other than F:\matlab or reloading will not work).  Invoking
//     >>myclass = cl.NewInstance('MyClass')
// creates a Matlab-accessible object.  After changing and recompiling MyClass,
//     >>myclass = cl.NewInstance('MyClass')
// will create a new object myclass that has the changes. 

import java.net.*;
import java.io.*;
import java.lang.reflect.*;

public class ClassLoad
{
    // Handler class required by Proxy -- all this handler does is forward all 
    // method calls using the reflection API invoke() method.
    class ProxyHandler implements InvocationHandler
    {
        private Object proxy_target;

        public ProxyHandler(Object target) {proxy_target = target;}

        public Object invoke(Object proxy, Method pmethod, Object[] params) 
            throws Exception
        {
            return pmethod.invoke(proxy_target,params);
        }
    }

    private URL[] urlL; // off-classpath search path list for reloadable class

    public ClassLoad(String pname) throws Exception
    {
        urlL = new URL[] {(new File(pname)).toURL()};
    }

    public Object NewInstance(String cname) throws Exception
    {
        ClassLoader ccl = Thread.currentThread().getContextClassLoader();
        ClassLoader cl = new URLClassLoader(urlL);
        Class c = Class.forName(cname,true,cl);
        Object o = c.newInstance();
        // Return proxy object because Matlab is otherwise unable to see
        // object in new class loader namespace.
        return Proxy.newProxyInstance(ccl,c.getInterfaces(),new ProxyHandler(o));
    }
}



//  In file F:\matlab\InPlace.java

// Copyright 2004 Paul Milenkovic, 118 Shiloh Dr., Madison, WI 53705 U.S.A.
// Free software: Permission granted to use, copy, excerpt or share this
// source code and derived executables provided that this notice is maintained.  

public interface InPlace
{
    public void SetParams(double[] params);

    public void Init(double sample_ms);

    public float[] Apply(float[] sig);
}



//  In file F:\matlab\myjava\SineFilter.java

// Copyright 2004 Paul Milenkovic, 118 Shiloh Dr., Madison, WI 53705 U.S.A.
// Free software: Permission granted to use, copy, excerpt or share this
// source code and derived executables provided that this notice is maintained.  

public class SineFilter implements InPlace
{
    // filter parameters
    private double freq_Hz = 100.0;
    private double magnitude = 1.0;
    private double phase = 0.0;
    // filter coefficients w, internal state y
    private double wr, wi;
    private double yr, yi;

    public void SetParams(double[] params)
    {
        if (params.length > 0)
            freq_Hz = params[0];
        if (params.length > 1)
            magnitude = params[1];
        if (params.length > 2)
            phase = params[2];
    }

    public void Init(double sample_ms)
    {
        // Calculate coefficients from filter parameters
        double Pi = 3.141592654;
        double iphase = 2*Pi*phase/360;
        double dphase = 2*Pi*freq_Hz*0.001*sample_ms;
        wr = Math.cos(dphase);
        wi = Math.sin(dphase);
        // Initialize state
        yr = magnitude*Math.cos(iphase);
        yi = magnitude*Math.sin(iphase);
    }

    public float[] Apply(float[] sig)
    {	
        for (int i = 0; i < sig.length; i++) 
        {
            double temp = yr*wr - yi*wi;
            sig[i] += (float) yr;
            yi = yr*wi + yi*wr;
            yr = temp;
        }
        return sig;
    }
}